Modification of anode surface in organic light-emitting diodes by chalcogenes

Influence of thin chalcogen X (S, Se, Te) interlayer between anode (indium-tin oxide, ITO) and a layer of N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) used as a hole-transport layer (HTL) on the operating characteristics of organic light-emitting diodes (OLEDs) of composition ITO/X/TPD/Alq(3)/Yb (Alq(3)-aluminum 8-quinolinolate) has been investigated. It was found that the sulphur layer decreases operating voltage and enhances operating stability of a device while the selenium or tellurium interlayers impair these characteristics. (c) 2008 Published by Elsevier B.V.